The central aim of this thesis is to investigate the association between extraversion and popularity. The thesis consists of three studies that consider key questions regarding this association. Each study focuses on a different set of when and why research questions, with some questions examined in two separate studies.
2.1 WHEN IS EXTRAVERSION ASSOCIATED WITH
POPULARITY?
1) Is extraversion already associated with popularity in middle childhood? (Study I)
Adding to the life-span generalizability of the link between extraversion and popularity, Study I examines this association among the youngest population context to date: seven- to eight-year-old children. Previous studies have found support for this association among adolescents (Ciarrochi & Heaven, 2009; Jensen-Campbell et al., 2002; Jensen-Campbell & Malcolm, 2007; Lubbers et al., 2006; Scholte et al., 1997; van der Linden et al., 2010) and young adults (Anderson et al., 2001; Asendorpf & Wilpers, 1998; Wortman & Wood, 2011), but the sample in Study I is the youngest in which this association has been examined with a sociometric nomination procedure that is reflective of the general popularity of a person. Although extraversion is known to be associated with popularity in older age groups, the setting for the presence of this association in regard to social environments (i.e. classrooms) and observable personality characteristics (Lönnqvist, Verkasalo, & Vainikainen, 2011) is already present at the beginning of the school year. Therefore, gaining popularity (or at least avoiding unpopularity) in such spontaneously forming system of social relations (Fournier, 2009) early in school could be influenced by extraversion.
2) Is extraversion associated with popularity in understudied and less talk-oriented cultures as well? (Studies I and II)
Study II provides another extension to the when of the extraversion- popularity link by analyzing this association among military cadets and their platoon-mates. For generalizability of the claim that extraversion and peer popularity are correlated in peer groups, it is important to illustrate not only that this correlation is not dependent on age but also that it generalizes beyond the populations that psychological research typically uses, such as American
psychology undergraduates with imbalanced gender ratios (Henrich et al., 2010). The environment of a military platoon provides a useful opportunity for this, and Study II investigates the association between extraversion and sociometric popularity within all-male military cadet platoons. Together with Study I, this is the first study to examine this association in Finland and Nordic countries. Therefore, the objective is also to examine if the stereotypically introverted and less talk-oriented culture influences this association.
3) Dimensional continuity: Are extraverts popular or introverts unpopular? (Studies II and III)
When also refers to the location on the introversion-extraversion continuum. To be generalizable across an entire construct continuum, the association between extraversion and popularity should exist at both ends and in the middle of a continuum that spans from extreme introversion to extreme extraversion (Paunonen & Hong, 2015). Studies II and III address this question by testing whether the association between trait introversion- extraversion and peer popularity is linear or if there is curvilinearity in the association whereby introverts are not unpopular in the same way that extraverts are popular, or vice versa.
4) Socio-ecological sensitivity: Does the number of peers in a social network influence the association between extraversion and popularity? (Study III)
Study III assesses the socio-ecological sensitivity of the extraversion- popularity association. It specifically tests if extraverts can attain increased popularity in the presence of a higher number of peers. The study explores the possibility of this socio-ecological sensitivity by determining whether the classroom size of first- and second-grade children moderates this association. The social centrality and attention gathering of extraverts (Ashton et al., 2002) could be especially functional in environments that contain a larger audience and less functional in environments with only a few available social partners. In addition, in larger classrooms, it is probably easier to switch between friends and peer groups, so individuals are not constrained to spending their time with the same group of classmates if they do not want to.
2.2 WHY IS EXTRAVERSION ASSOCIATED WITH
POPULARITY?
5) Do dyadic combinations of extraversion drive the association between extraversion and popularity? (Studies II and III)
Studies II and III concern the interpersonal sensitivity of the extraversion- popularity link. Dyadic combinations of introversion-extraversion could serve as explanations for the popularity (unpopularity) of extraverts (introverts) on a group level. There are two contradicting propositions that both expect extraverts to be more popular since conferring popularity to others is also dependent on the extraversion of those admitting popularity (or personal preference) to others. First, it could be that individuals who are similar in extraversion prefer each other, and extraverts prefer each other even more strongly than introverts do (Selfhout et al., 2010; van Zalk & Denissen, 2015). This association would be revealed by an asymmetric homophily effect (McPherson et al., 2001) that would be stronger at the extraverted end of the introversion-extraversion continuum. Second, extraverts could be more popular because introverts tend to prefer extraverts (Dryer & Horowitz, 1997), but this reciprocity would only exist from introversion to extraversion, not vice versa. Both propositions can be analyzed and demonstrated through polynomial regression analysis accompanied by RSA (Edwards, 2002), a statistical method that has not been previously used for dyadic personality- popularity examinations.
6) Is extraversion associated with popularity because of the higher oral fluency of extraverts? (Study I)
Study I explores the potential mediating mechanism that underlies this association. In studies of the social consequences of personality, it is important to understand the processes of specific mediating mechanisms between personality traits and the social domain. The proposed mediator that intertwines in the process from extraversion to popularity in peer system is oral fluency, i.e. the capacity for fluent verbal communication. The potency of this mediator is likely to be strong among the young cohort in Study I (seven- to eight-year-old children), which is likely to present individual differences in oral fluency.